Tip & How-To about Plumbing

Water Heaters go Tankless

You may or may not have heard about these cool little devices by now, but if not, here is the low down.

Tankless water heaters are used all across Europe and come in several varieties.

1. Natural gas fired on demand Tankless
2. Oil Fired Tankless
3. Electrical Tankless

The most prevalent among these is the gas fired version.

In America, these energy savers are just starting to gain a foothold.
Leaders in the field are Titan, Bosch, Rinnai, and Noritz to name a few.

The real benefit to Tankless over Standard water heaters is that you never waste energy heating water that sits in a tank cooling until you use it.
If you have a 20 to 80 gallon water in your home, it will run night and day at odd internals maintaining it's own heat.

What this means to you is that in a typical day, whether you use hot water that day or not, is that your water heater will cycle many times to maintain it's heat whether the hot water is used or not.

Some people try to drive this wasted energy use down by wrapping their water heater with thermal blankets, or by insulating the water heater closet itself, which has only proven to be partially effective.

Also bear in mind that these Tankless water heaters are quite small compared to the Tank version, some are as small as 18 by 12 inches.
This means that your old water heater closet can now be used to store your valuables without fear of starting a fire.

A further waste of energy occurs when the exhaust heat is funneled to the outside when it could have been diverted to a heat exchanger or other energy conservation device.

Tankless water heaters perform far better in energy use than the old school, Tank type water heater by simply heating water exactly when it is needed, then shutting down when the hot water tap is turned off.
What this means for you, the consumer is that you will have hot water any time you need it, and the water will remain hot as long as the hot water tap is opened.

There are virtually no cold water periods for a tankless water heater.
You have an endless stream of hot water, without wasting a single BTU of heat, kilowatt of electricity, or ounce of natural gas.

The real surprise here is that nobody really knows just how much their utility bill is being affected by that Tank style water heater until the first utility bill arrives. The savings are immediate and significant, both in terms of less energy consumption and Dollars saved.

Let me drive that point home in real life terms.
You definitely will NOT use MORE energy after your install.
You will most Certainly use less!

There are several typical applications for Tankless systems in any common home.

1. Low Volume On Demand heaters can be installed under the sink.
2. High Volume Tankless Whole House heaters supply the entire home.
3. On demand Budget Tankless heaters can be located at the sink coupled with whole house heaters for faster hot water delivery to eliminate cold spots. These are the most popular for the beginner Tankless solutions.
Your cold water pipe is split from the cold water valve itself to the Tankless heater under the sink as well as the cold water tap. The hot water outlet is then connected to the Tankless water heater under the sink to provide instant hot water, eliminating the need for a hot water tap from the main hot water supply. This results in even less energy waste since the smaller Tankless heater uses less energy than a whole house Tankless unit.
4. On demand Tankless heaters use virtually no energy to heat unused water. When the hot water tap is off, the Tankless unit is off.

The price point for these Tankless models is fairly competitive against a standard water heater, but can sometimes be more expensive depending on the model and water volume you require. What matters most though is that these Tankless versions begin paying for themselves the day they are installed.

My final word on this is simple.
Most other countries in the world have been using tankless water heaters for a very long time due to natural gas and oil prices. Their adoption of these devices is a necessity rather than a purchase of convenience.
In terms of technology, America falls close to last place in this field, as well as many other areas where energy consumption is a factor.

When you purchase a Tankless water heater, you not only save money, but you also help the environment by wasting less energy to heat the same amount of water you consume on a per use basis. You will also use somewhat less water since you no longer have to wait for that cold water to leave the tap so the hot water will finally flow.

The choice is yours.
Choose wisely!

Please Vote for this Tip if you found it helpful.
Bob S.

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2 Answers

hot water varies


I do not know how old this unit is or what model but many water heaters are not sophisticated enough to measure the temperature, but heat based on water flow and temperature rise. To start, tankless water heaters turn off every time you turn the hot water off. Lets use an example. You use the facilities, wash your hands then turned off the water and take a shower. You will bring the already heated water (from washing your hands) from the pipe up to the shower. Then the cold water that comes into the pipe from the reactivation of the water heater comes up the hot water pipe with warm then hot water just behind.

If this is not your problem, keep reading. Every unit I have been called to see were installed wrong. Check your installation manual to see if the problem with the system started with the contractor.

First, check the temperature of the water from the heater. If it is too hot and you are mixing too much cold water in, the unit will turn off because there is not enough water flow to keep it running.

Second, turn off the valve at the water heater and turn on the hot water at a faucet. If the water does not stop running, there is a "plumbing cross over" usually caused by a failing pressure balance valve in a shower.

Third, if the unit has not been serviced, go to bosch-climate.us to find a tankless water heating professional in your area. Totally Tankless LLC

Mar 14, 2014 | Bosch & Tankless LP Hot Water Heater

1 Answer

there is power to the system but when you turn water on elements do not come one and heat water. all phases have 238 volts to them. why will system not turn on and heat water


Do you have 3-phase water heater? Is this balanced or unbalanced 3-phase unit. Add comment and describe product in detail, including brand since i have some service resources for both types.
Or do you have ordinary residential split-phase 240Volt Bosch tankless computer that heats water, and has 2 or 3 separate elements, and a separate circuit breaker supplying power to each element? And testing across both hot leads coming from each breaker yields 238Volt?
Copy following link for Bosch tankless manuals, with brief troubleshoot section that does not provide detailed service procedures for repairing tankless computer:
http://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.html#manual
If this is new water heater, then call installer. If you installed yourself, then remove tankless and return to seller for refund.
Tankless computers require certain amount of water flow to activate computer sensors. Turn on Hot tap and listen to pipe to hear if water if flowing through hot pipe. Check for crossover:
http://waterheatertimer.org/Crossover.html
Clean water filter usually located just above where cold water connects to unit.
Delime tankless ... and use water softener. Tankless cannot be exposed to more than 11 grains hardness in water, or parts will fail within 2-3 years. Simply deliming tankless heat exchanger each year will not maintain full efficiency... although for typical family of 4, tankless comper water heater costs $100 more to operate than tank-type heater according to manufacturer's promo literature and independent studies.
Call local technician who specializes in fixing tankless computers. For plumbing problems call local plumber. These are two different things.
If tankless computer is older, then cut losses, and buy tank-type electric water heater at Lowes for $285 and make quick changeover and have hot water same day. Sell old tankless on ebay and cheat next guy, or sell at scrapyard for $3 per 100.
Gene
h

Aug 05, 2013 | Bosch PowerStar AE125 AE125 Whole House...

1 Answer

little to no flow through unit


Check for crossover:
http://waterheatertimer.org/Crossover.html
Clean water filter located just above where water enters unit.
Copy following link for Bosch powerstar manuals with brief troubleshoot section in each;
http://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.html#manual
Call service technician who is qualified to work on computer that heats water. For plumbing problems, call local plumber. These are two different things.
Fix any brand tankless yourself, same day, by replacing the whole thing. Buy electric water heater at Lowes for $285 and be up and running by sundown.
Gene
h

Aug 05, 2013 | Bosch PowerStar AE9.5 Electric Tankless...

1 Answer

The heater is only kicking on low as the wate demand goes up the temperature of the water drops because the heater is not kicking up like it used to. The heater is a little over a year old.


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-Tankless water heaters are susceptible to lime build-up if not de-limed each year.
-Hard water will clog pressure-sensor and cause failure within 2 years if filter and softener are not working.
-Water flow and water pressure sensors inside tankless are succeptible to hard water deposits.
-Low water pressure from clogged pipes to municipal water problems to water well pressure valve can affect tankless burner
-Low-flow shower heads may not engage burner.
-With tankless-gas water heaters, sensors inside combustion area detect when incoming air flow is not adequate ... inspect inflow
-Your manual probably has a troubleshoot section.
-The manufacturer will refer you to installer.
-If you self-installed unit, that will void warranty to my understanding.
-There are water heater forums 1 2 3 4
-There are plumbers who will each have a different opinion
-There are Fixya experts who get paid to tell you the above.
-And there are local plumbers who are authorized dealers of the brand of tankless who get paid to fix them

Oct 07, 2010 | Rheem Tankless Hot Water Heater...

1 Answer

How do you sdjust dip switches on an ECO200PV for 125 degree water?


why so hot? one thing i have noticed when i install tankless is we are soo used to making hotter water then we need then cooling it down to what we like, set your tankless so when you jump in the shower or do the dishes that you only turn on hot water only. then your not wasting energy to heat water you are just cooling down. then your just heating water to what it needs to be. you will use less energy and get more out put out of your tankless

Jul 28, 2009 | Rheem Tankless Hot Water Heater...

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